CN109462354B - Method for suppressing speed fluctuation of single-rotor compressor - Google Patents

Abstract

The invention discloses a method for suppressing the speed fluctuation of a single-rotor compressor, which includes a process of controlling the compressor according to real-time angular velocity and torque; the process of controlling the compressor according to the real-time angular velocity includes: filtering shaft errors to obtain angular velocity compensation Compensate the angular velocity compensation into the output angular velocity of the phase-locked loop regulator to obtain the compensated angular velocity output; correct the real-time angular velocity according to the compensated angular velocity output, and control the compressor according to the corrected real-time angular velocity The process of controlling the compressor according to the torque includes: calculating the difference between the fluctuation amount of the target angular velocity and the feedback angular velocity amount to obtain a first angular velocity difference; filtering the first angular velocity difference to obtain a filtered angular velocity; Input to the speed loop regulator to obtain the output torque; control the compressor according to the output torque. By applying the present invention, the effectiveness of suppressing the fluctuation of the compressor rotational speed can be improved.

Description

Method for suppressing fluctuation of rotation speed of single-rotor compressor

Technical Field

The invention belongs to the technical field of motor control, particularly relates to a compressor control technology, and more particularly relates to a method for inhibiting the rotation speed fluctuation of a single-rotor compressor.

Background

When the single-rotor compressor used by the air conditioner runs, the single-rotor compressor is influenced by the working principle and the control technology of the air conditioner serving as a load, so that the load torque of the compressor is extremely unstable, large rotation speed fluctuation is easily caused, and the running of the compressor is not stable. The unstable operation of the compressor can cause the unstable operation of the whole air conditioner system, resulting in various adverse effects. And unstable operation can also produce great operating noise, can not satisfy relevant noise standard requirement, influences air conditioner and uses the travelling comfort. This phenomenon is particularly serious in a single-rotor compressor.

Although the prior art also has a method for controlling the rotating speed of the compressor, the effect of inhibiting the rotating speed fluctuation is not ideal enough, and the problem of the rotating speed fluctuation of the compressor cannot be fundamentally solved.

Disclosure of Invention

The invention aims to provide a method for restraining the rotation speed fluctuation of a single-rotor compressor, which improves the effectiveness of restraining the rotation speed fluctuation of the compressor.

In order to realize the purpose of the invention, the invention is realized by adopting the following technical scheme:

a method for suppressing rotation speed fluctuation of a single rotor compressor, the method comprising a process of controlling the compressor according to a real-time angular speed and a process of controlling the compressor according to a torque;

the process of controlling the compressor according to the real-time angular velocity includes:

acquiring a shaft error delta theta reflecting a deviation between an actual position and an estimated position of a compressor rotor;

filtering the axis error delta theta to obtain a corrected axis error delta theta 'and an angular speed compensation quantity P _ out corresponding to the corrected axis error delta theta' after at least part of axis error fluctuation is filtered;

compensating the angular velocity compensation quantity P _ out into an output angular velocity delta omega _ PLL of a phase-locked loop regulator in the phase-locked loop for controlling the compressor to obtain compensated angular velocity output quantity delta omega ', and obtaining delta omega' ═ P _ out + delta omega _ PLL;

correcting the real-time angular speed omega 1 for controlling the compressor according to the compensated angular speed output quantity delta omega', and controlling the compressor according to the corrected real-time angular speed omega 1;

the process of controlling the compressor according to the torque includes:

calculating the difference between the target angular velocity fluctuation amount and the feedback angular velocity amount to obtain a first angular velocity difference value; the feedback angular velocity amount is the sum of the direct current component P _ DC of the angular velocity compensation amount P _ out and the compensated angular velocity output amount Δ ω';

filtering the first angular velocity difference to obtain a filtered angular velocity at least filtering part of angular velocity fluctuation;

inputting the filter angular velocity as an input quantity to a speed ring regulator in a speed ring for controlling a compressor, and obtaining an output torque of the speed ring regulator;

controlling the compressor according to the output torque;

the filtering the first angular velocity difference to obtain a filtered angular velocity at least after filtering part of angular velocity fluctuation, specifically comprising:

and extracting partial angular velocity fluctuation in the first angular velocity difference by adopting a velocity fluctuation extraction algorithm, extracting a direct current component of the partial angular velocity fluctuation, calculating a difference between the first angular velocity difference and the direct current component of the partial angular velocity fluctuation, and determining the difference as the filtering angular velocity.

Compared with the prior art, the invention has the advantages and positive effects that: the invention provides a method for restraining the fluctuation of the rotating speed of a single-rotor compressor, which filters out the fluctuation of a shaft error delta theta reflecting the deviation of the actual position and the estimated position of a compressor rotor, compensates the angular speed compensation quantity corresponding to the corrected shaft error after at least part of the shaft error fluctuation is filtered out into the output angular speed of a phase-locked loop regulator to obtain the compensated angular speed output quantity, corrects the real-time angular speed of the compressor according to the compensated angular speed output quantity, and can enable the fluctuation quantity and the phase position of the target rotating speed to be close to the fluctuation quantity and the phase position of the actual rotating speed when the compressor is controlled by the corrected real-time angular speed so as to lead the operation of the compressor to tend to be stable; moreover, because the fluctuation of the shaft error is a front end direct factor causing speed fluctuation, the periodical fluctuation of the shaft error is reduced by filtering the fluctuation of the shaft error at the front end, the speed fluctuation can be directly and quickly inhibited, and the effectiveness of speed control is improved. In addition, the difference value between the feedback angular velocity quantity and the target angular velocity fluctuation quantity is subjected to filtering processing, and the filtering angular velocity after at least part of angular velocity fluctuation is filtered is input into the speed loop regulator as an input quantity, so that the fluctuation of the output torque of the speed loop regulator can be reduced, and when the compressor is controlled according to the output torque, the fluctuation of the rotating speed of the compressor can be reduced, and the operation of the compressor is more stable; the compressor operates stably, and the effects of energy conservation and vibration reduction can be achieved.

Other features and advantages of the present invention will become more apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.

Drawings

FIG. 1 is a partial flow chart of one embodiment of a method for suppressing rotational speed fluctuations of a single rotor compressor in accordance with the present invention;

FIG. 2 is another partial flow chart of an embodiment of a method for suppressing rotational speed fluctuations of a single rotor compressor in accordance with the present invention;

FIG. 3 is a control block diagram based on the method embodiment of FIGS. 1 and 2;

FIG. 4 is a logic block diagram of a specific example of the axis error fluctuation filtering algorithm of FIG. 3;

FIG. 5 is a logic block diagram of a specific example of the speed fluctuation extraction algorithm of FIG. 3.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and examples.

Fig. 1 and 2 each show a partial flow chart of an embodiment of a method for suppressing rotational speed fluctuations of a single-rotor compressor according to the invention. Specifically, the method of suppressing the rotation speed fluctuation of the embodiment includes two processes: one is a process for controlling the compressor according to the real-time angular velocity, and the flow chart is shown in fig. 1; one is a process of controlling the compressor according to the torque, and the flowchart is shown in fig. 2. Specific implementations of these two processes are described below based on a control block diagram shown in fig. 1 and 2 in conjunction with fig. 3.

Referring to fig. 1, a partial flowchart of an embodiment of a method for suppressing rotational speed fluctuations of a single-rotor compressor according to the present invention, specifically a flowchart for controlling a compressor according to a real-time angular velocity, is shown, which is implemented by a process including the following steps:

step 11: a shaft error Delta theta reflecting a deviation between an actual position and an estimated position of a compressor rotor is acquired.

In the control of the compressor, the phase of the compressor rotor can be locked to the target phase by a phase-locked loop (PLL) control technique, the control block of which is shown in fig. 3. In the prior art, a phase-locked loop regulator, typically a proportional-integral regulator, is included in the phase-locked loop of the compressor, see K of fig. 3_{P_PLL}And K_{I_PLL}and/S. The axis error Δ θ is used as an input of the PLL regulator, and specifically, the axis error Δ θ is subtracted from a target angular fluctuation amount (0 shown in fig. 3), and the difference is input to the PLL regulator, and the output of the PLL regulator is an output angular velocity Δ ω _ PLL. Based on the output angular velocity Δ ω _ PLL of the phase-locked loop regulator, the phase-locked loop outputs a real-time angular velocity ω 1 for compressor control, and the rotor position is controlled using the real-time angular velocity ω 1.

The shaft error Δ θ, which reflects the deviation between the actual position and the estimated position of the compressor rotor, can be calculated by the following equation:

in the formula, the first step is that,

and

respectively a d-axis voltage set value and a q-axis voltage set value of the compressor, I_dAnd I_qReal-time d-axis current and real-time q-axis current, r, of the compressor, respectively^*Is the resistance of the motor of the compressor,

is the q-axis inductance, omega, of the compressor₁Is the real-time angular frequency of the compressor. Among the parameters, I_d、I_qAnd ω₁The detection is carried out in real time by the detection means in the prior art, and other parameter values are known values.

Step 12: and filtering the axis error delta theta to obtain a corrected axis error delta theta' after at least part of axis error fluctuation is filtered.

Since the shaft error is used as an input to the phase locked loop, the real-time angular velocity of the compressor at the output of the phase locked loop is affected. If the shaft error fluctuation is large, the real-time angular speed output by the phase-locked loop is unstable, so that the rotor phase locking is unstable, and further, the compressor has faults of overcurrent, step loss and the like.

After the axis error Δ θ is obtained in step 11, filtering is performed on the axis error Δ θ to filter at least a part of fluctuation components, so as to obtain a corrected axis error Δ θ' after filtering at least a part of axis error fluctuation. The method for filtering the shaft error can be implemented by adopting the prior art, and more preferably, the filtering process is described in the following preferred embodiments.

Step 13: the angular velocity compensation amount P _ out is obtained from the corrected shaft error Δ θ'.

This step can be implemented in a manner of obtaining the angular velocity according to the angle in the prior art. The more preferable processing manner is described in the following preferable embodiment.

The implementation of the above step 12 and step 13 is reflected in the control block diagram of fig. 3, and an axis error fluctuation filtering algorithm is adopted to obtain the angular velocity compensation amount P _ out.

Step 14: the angular velocity compensation amount P _ out is compensated to the output angular velocity delta omega _ PLL of the phase-locked loop regulator in the phase-locked loop for controlling the compressor, and the compensated angular velocity output amount delta omega' is obtained. Specifically, the compensated angular velocity output amount Δ ω' ═ P _ out + Δ ω _ PLL.

Step 15: and correcting the real-time angular speed omega 1 for controlling the compressor according to the compensated angular speed output quantity, and controlling the compressor according to the corrected real-time angular speed omega 1.

Specifically, the method of determining the real-time angular velocity corresponding to the target angular velocity fluctuation amount of 0 in the following velocity loop control is: referring to fig. 3, the compensated angular velocity output amount Δ ω' is added to the angular velocity command ω × in, and the real-time angular velocity ω 1 for controlling the compressor is output. The angular velocity command ω _ in is a given angular velocity value of the compressor control system, and the determination method of the value of the given angular velocity command ω _ in is implemented by using the prior art. The target angular velocity fluctuation quantity of the speed loop is 0, and the real-time angular velocity is determined based on the output angular velocity delta omega _ PLL of the phase-locked loop regulator and the given angular velocity command omega _ in, so that the compressor is controlled more accurately and stably.

Referring to fig. 2, a partial flowchart of an embodiment of a method for suppressing rotational speed fluctuations of a single-rotor compressor according to the present invention, specifically a flowchart for controlling a compressor according to torque, is shown, which is implemented by a process including the following steps:

step 21: and calculating the difference between the target angular velocity fluctuation amount and the feedback angular velocity amount to obtain a first angular velocity difference value. The feedback angular velocity amount is the sum of the direct current component P _ DC of the angular velocity compensation amount P _ out and the compensated angular velocity output amount Δ ω'.

In compressor control, the rotational speed of the compressor rotor can be controlled by speed loop (ASR) control techniquesTo approach the set rotation speed. Referring to the block diagram of FIG. 3, the speed loop includes a speed loop regulator, typically a proportional integral regulator, see K of FIG. 3_{P_ASR}And K_{I_ASR}/S。

In this step, both the direct current component P _ DC of the angular velocity compensation amount P _ out and the compensated angular velocity output amount Δ ω' are used as inputs to the velocity loop. Specifically, the direct current component P _ DC of the angular velocity compensation amount P _ out is extracted, and the sum of the direct current component P _ DC and the compensated angular velocity output amount Δ ω 'is calculated to obtain the feedback angular velocity amount Δ ω 1, where Δ ω 1 is P _ DC + Δ ω'. The extraction of the DC component P _ DC of the angular velocity compensation amount P _ out can be realized by using a conventional technique for extracting a DC component, for example, by using a low-pass filter to extract the DC component P _ DC of the angular velocity compensation amount P _ out.

Then, a difference between the target angular velocity fluctuation amount and the angular velocity output amount Δ ω' is calculated, and the difference therebetween is determined as a first angular velocity difference Δ ω 2. Here, the target angular velocity fluctuation amount is a desired angular velocity fluctuation amount and is a known input amount. As a preferred embodiment, in this example, the target angular velocity fluctuation amount is 0.

Step 22: and performing filtering processing on the first angular velocity difference to obtain a filtered angular velocity after at least part of angular velocity fluctuation is filtered.

The first angular velocity difference is used as an input to the velocity loop regulator to affect the output torque at the velocity loop output. If the first angular speed difference value fluctuates greatly, the fluctuation of the output torque is large, and further the fluctuation of the rotating speed of the compressor is large. After the first angular velocity difference is obtained in step 21, a filtering process is performed on the first angular velocity difference to filter out at least part of the angular velocity fluctuation component, so as to obtain a filtered angular velocity Δ ω _ K.

Specifically, as shown in the block diagram of fig. 3, the filtering processing is performed on the first angular velocity difference Δ ω 2 to obtain a filtered angular velocity Δ ω _ K at least after part of the angular velocity fluctuation is filtered, which specifically includes: extracting partial angular velocity fluctuation K _ out in the first angular velocity difference delta omega 2 by adopting a velocity fluctuation extraction algorithm, and extracting a direct current component K _ DC of the partial angular velocity fluctuation K _ out; then, a difference between the first angular velocity difference Δ ω 2 and the direct current component K _ DC of the partial angular velocity fluctuation is calculated, and the difference is determined as a filtered angular velocity Δ ω _ K. The extraction of the DC component K _ DC of the partial angular velocity fluctuation K _ out can be realized by using the existing technology of extracting the DC component, for example, by using a low-pass filter to extract the DC component K _ DC of the partial angular velocity fluctuation K _ out. For a more preferable filtering processing manner, refer to the description of the following preferred embodiments.

Step 23: inputting the angular speed of the filter as input quantity to a speed loop regulator in a speed loop for controlling the compressor to obtain the output torque tau of the speed loop regulator_M。

Step 24: and controlling the air conditioner compressor according to the output torque. The specific control process refers to the prior art.

By adopting the method of the embodiment formed by the above-mentioned fig. 1 and fig. 2, the double loop control of the speed loop and the phase-locked loop of the compressor is realized. In addition, in the phase-locked loop control, the fluctuation filtering is carried out on the shaft error delta theta reflecting the deviation between the actual position and the estimated position of the compressor rotor, the angular speed compensation quantity corresponding to the corrected shaft error after at least part of the shaft error fluctuation is filtered is compensated to the output angular speed of the phase-locked loop regulator, the compensated angular speed output quantity is obtained, the real-time angular speed of the compressor is corrected according to the compensated angular speed output quantity, and when the compressor is controlled by the corrected real-time angular speed, the variation quantity and the phase of the target rotating speed can be close to the variation quantity and the phase of the actual rotating speed, so that the operation of the compressor tends to be stable. Moreover, because the fluctuation of the shaft error is a front end direct factor causing speed fluctuation, the periodical fluctuation of the shaft error is reduced by filtering the fluctuation of the shaft error at the front end, the speed fluctuation can be directly and quickly inhibited, and the effectiveness of speed control is improved. In the control of the speed loop, the difference value between the feedback angular velocity quantity and the target angular velocity fluctuation quantity is subjected to filtering treatment, and the filtered angular velocity with at least part of angular velocity fluctuation filtered out is input into the speed loop regulator as an input quantity, so that the fluctuation of the output torque of the speed loop regulator can be reduced, and when the compressor is controlled according to the output torque, the fluctuation of the rotating speed of the compressor can be reduced, and the operation of the compressor is more stable; the compressor operates stably, and the effects of energy conservation and vibration reduction can be achieved.

In some other embodiments, the filtering the axis error Δ θ to obtain a corrected axis error Δ θ' after at least part of the axis error fluctuation is filtered, specifically includes: and filtering the axis error delta theta to filter at least the first harmonic component in the delta theta and obtain a corrected axis error delta theta' in which at least the first harmonic component is filtered. In a more preferred embodiment, the filtering process is performed on the axis error Δ θ, and includes filtering the first harmonic component and the second harmonic component in Δ θ to obtain a corrected axis error Δ θ' with the first harmonic component and the second harmonic component filtered. Most of fluctuation components in the delta theta can be filtered out by filtering out the first harmonic component or the first harmonic component and the second harmonic component in the delta theta, the calculated amount is moderate, and the filtering speed is high.

Fig. 4 is a logic block diagram showing a specific example of the axis error fluctuation filtering algorithm in fig. 3, specifically, a logic block diagram showing a specific example of obtaining the angular velocity compensation amount P _ out corresponding to the corrected axis error Δ θ' after filtering the first harmonic component and the second harmonic component in the axis error Δ θ. The specific acquisition process is as follows:

firstly, the axis error delta theta is subjected to Fourier series expansion to obtain the axis error delta theta relative to the mechanical angle theta_mIs used for the functional expression of (1). The method comprises the following specific steps:

in the formula,. DELTA.theta._DCIs the direct component of the axis error, θ_{d_n}＝θ_{peak_n}cosφ_n，θ_{q_n}＝θ_{peak_n}sinφ_n，

Δθ_{peak_n}For the n harmonic axis error fluctuation amplitude, theta_m1、θ_m2Is the first harmonic mechanical angle. And second harmonic mechanical angle theta_m2Expressed as: theta_m2＝2θ_m1。

And then, extracting a first harmonic component and a second harmonic component from the function expression, and filtering the first harmonic component and the second harmonic component by adopting an integrator to obtain a filtering result.

Specifically, the first harmonic component and the second harmonic component can be extracted from the above functional expression by using a low-pass filtering method or an integration method. With particular reference to FIG. 4, the functional expressions are each related to cos θ_m1And cos θ_m2After multiplication, a low-pass filter is used for filtering or an integrator is used for taking an integral average value in a period, and a d-axis component of a first harmonic and a d-axis component of a second harmonic of an axis error delta theta are extracted; respectively comparing the function expressions with-sin theta_m1And-sin θ_m2After multiplication, the q-axis component of the first harmonic and the q-axis component of the second harmonic of the axis error delta theta are extracted by filtering through a low-pass filter or taking an integral average value in a period through an integrator. Then, the d-axis component and the q-axis component of the first harmonic and the d-axis component and the q-axis component of the second harmonic are respectively subtracted from 0, and the resultant is input to an integrator K_{I_P}And performing integral filtering treatment in the step S to obtain a filtering result for filtering the first harmonic component and the second harmonic component, wherein the filtering result is changed into the angular velocity.

Then, each filtering result is subjected to inverse fourier transform, and an angular velocity compensation amount P _ out corresponding to the correction axis error Δ θ' in which the first harmonic component and the second harmonic component are filtered is obtained. Specifically, the filtering result of the d-axis component for filtering the first harmonic and the filtering result of the q-axis component for filtering the first harmonic are respectively subjected to the sum of results after inverse fourier transform, so as to form an angular velocity compensation quantity P _ out1 corresponding to the correction axis error for filtering the first harmonic component; the filtering result of the d-axis component for filtering the second harmonic and the filtering result of the q-axis component for filtering the second harmonic are respectively subjected to the sum of results after Fourier inverse transformation, and an angular velocity compensation quantity P _ out2 corresponding to the correction axis error for filtering the second harmonic component is formed; the sum of the two angular velocity compensation amounts forms an angular velocity compensation amount P _ out of P _ out1+ P _ out2 corresponding to the correction axis error Δ θ' in which the first harmonic component and the second harmonic component are filtered out.

As a preferred embodiment, the control of harmonic filtering can also be achieved by adding an enable switch. Specifically, in the block diagram of fig. 4, Gain _1 and Gain _2 are enable switches for determining whether to turn on/off the filtering algorithm function. In the case where the enable switch states of Gain _1 and Gain _2 are the functions of filtering the first harmonic and filtering the second harmonic, the angular velocity compensation amount P _ out corresponding to the correction axis error Δ θ' of filtering the first harmonic component and the second harmonic component is obtained as P _ out1+ P _ out 2. If the enable switch states of Gain _1 and Gain _2 are the functions of filtering the first harmonic and the second harmonic, the whole axis error filtering function is turned off, and the angular velocity compensation amount P _ out cannot be output. If one of the enable switches is in the state of turning on the filtering algorithm function, and the other enable switch is in the state of turning off the filtering algorithm function, the obtained angular velocity compensation quantity P _ out is only the angular velocity compensation quantity for filtering the first harmonic (the Gain _1 enable switch is in the state of turning on the filtering first harmonic function, and the Gain _2 enable switch is in the state of turning off the filtering second harmonic function), or is only the angular velocity compensation quantity for filtering the second harmonic (the Gain _1 enable switch is in the state of turning off the filtering first harmonic function, and the Gain _2 enable switch is in the state of turning on the filtering second harmonic function).

In the embodiment of filtering only the first harmonic component, the process of extracting the first harmonic component and filtering the first harmonic component in fig. 4 may be directly adopted. Of course, in the embodiment of filtering only the first harmonic component, the control of filtering the first harmonic component may also be implemented by adding an enable switch, and the specific implementation manner is also referred to fig. 4 and will not be repeated herein.

In some other preferred embodiments, the extracting, by using a speed fluctuation extraction algorithm, a part of the angular velocity fluctuation in the first angular velocity difference specifically includes: and extracting at least a first harmonic component in the first angular velocity difference value by adopting a velocity fluctuation extraction algorithm to serve as a part of angular velocity fluctuation. As a more preferable embodiment, the extracting, by using a speed fluctuation extraction algorithm, part of the angular speed fluctuation in the first angular speed difference includes: and extracting a first harmonic component and a second harmonic component in the first angular velocity difference value by adopting a velocity fluctuation extraction algorithm, and taking the sum of the first harmonic component and the second harmonic component as part of angular velocity fluctuation. After the difference value is obtained between the first angular velocity difference value and the first harmonic component, most of fluctuation components in the first angular velocity difference value can be filtered, the calculated amount is moderate, and the filtering speed is high.

Fig. 5 is a logic block diagram showing a specific example of the speed fluctuation extraction algorithm in fig. 3, specifically, a logic block diagram showing a specific example of extracting the first harmonic component and the second harmonic component from the first angular velocity difference value to form a partial angular velocity fluctuation. Referring to fig. 5, this specific example obtains a partial angular velocity fluctuation containing a first harmonic component and a second harmonic component by the following method:

firstly, a Fourier series expansion is carried out on the first angular velocity difference delta omega 2 to obtain the first angular velocity difference delta omega 2 relative to the mechanical angle theta_mIs used for the functional expression of (1). This process can be implemented using existing technology and is not described in detail here.

Then, the first harmonic component and the second harmonic component are extracted from the functional expression, respectively.

Specifically, as shown in FIG. 5, the functional expression is related to cos θ_m1After multiplication, pass through a low-pass filter

Filtering, and performing inverse Fourier transform on a filtering result to obtain a d-axis component of the first harmonic; multiplying the functional expression by-sin θ_m1After multiplication, pass through a low-pass filter

Filtering, and performing inverse Fourier transform on a filtering result to obtain a q-axis component of a first harmonic; then, the d-axis component and the q-axis component of the first harmonic are added to obtain a first harmonic component K _ out1 in the first angular velocity difference. Similarly, the functional expression is related to cos θ_m2After multiplication, pass through a low-pass filter

Filtering, and performing inverse Fourier transform on a filtering result to obtain a d-axis component of a second harmonic; multiplying the functional expression by-sin θ_m2After multiplication, pass through a low-pass filter

Filtering, and performing inverse Fourier transform on a filtering result to obtain a q-axis component of a second harmonic; then, the d-axis component and the q-axis component of the second harmonic are added to obtain a second harmonic component K _ out2 in the first angular velocity difference. Finally, the first harmonic component K _ out1 is added to the second harmonic component K _ out2, and the resulting sum forms part of the angular velocity fluctuation K _ out. Wherein, theta_m1Mechanical angle of first harmonic, theta, in a functional expression developed as a Fourier series_m2Mechanical angle of the second harmonic in a functional expression developed as a Fourier series, and θ_m2＝2θ_m1，T_{_PD_filter}Is the time constant of the low pass filter.

After obtaining the partial angular velocity fluctuation K _ out containing the first harmonic component and the second harmonic component, calculating a difference between the first angular velocity difference Δ ω 2 and the partial angular velocity fluctuation K _ out as a filtered angular velocity Δ ω _ K, where the filtered angular velocity Δ ω _ K is the filtered angular velocity after the first harmonic component and the second harmonic component are filtered out.

As a preferred embodiment, the control of the harmonic extraction can also be achieved by adding an enable switch. Specifically, in the block diagram of fig. 5, Gain _1 and Gain _2 are enable switches for determining whether to turn on/off the extraction algorithm function. Under the condition that the enabling switch states of the Gain _1 and the Gain _2 are on, the functions of extracting the first harmonic and extracting the second harmonic are obtained, and partial angular velocity fluctuation formed by the first harmonic component and the second harmonic component is obtained: k _ out is K _ out1+ K _ out 2. If the enable switch states of Gain _1 and Gain _2 are the functions of extracting the first harmonic and extracting the second harmonic, the whole speed fluctuation extraction algorithm function is turned off, and part of the angular speed fluctuation is 0. If one of the enable switches is in the state of opening the extraction algorithm function, and the other enable switch is in the state of closing the extraction algorithm function, the obtained part of the angular speed fluctuation is only a first harmonic component in the first angular speed difference (the state of the Gain _1 enable switch is in the state of opening the extraction first harmonic function, and the state of the Gain _2 enable switch is in the state of closing the extraction second harmonic function) or only a second harmonic component in the first angular speed difference (the state of the Gain _1 enable switch is in the state of closing the extraction first harmonic function, and the state of the Gain _2 enable switch is in the state of opening the extraction second harmonic function).

In the embodiment of extracting only the first harmonic component, the process of extracting the first harmonic component in fig. 5 may be directly employed; of course, the control of the first harmonic extraction may also be implemented by adding an enable switch, and the specific implementation manner is also shown in fig. 5, which is not repeated herein.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims (10)

1. a method for suppressing the fluctuation of the rotational speed of a single-rotor compressor, characterized in that the method comprises the process of controlling the compressor according to the real-time angular velocity and the process of controlling the compressor according to the torque; The process of controlling the compressor according to the real-time angular velocity includes: Obtain the shaft error Δθ reflecting the deviation between the actual position and the estimated position of the compressor rotor; Perform filtering processing on the shaft error Δθ to obtain a corrected shaft error Δθ' after filtering out at least part of the shaft error fluctuation and an angular velocity compensation amount P_out corresponding to the corrected shaft error Δθ'; Compensating the angular velocity compensation amount P_out into the output angular velocity Δω_PLL of the phase-locked loop regulator in the phase-locked loop for compressor control to obtain the compensated angular velocity output amount Δω', Δω'=P_out+Δω_PLL; The real-time angular velocity ω1 used for compressor control is corrected according to the compensated angular velocity output Δω', and the compressor is controlled according to the corrected real-time angular velocity ω1; The process of controlling the compressor according to the torque includes: Calculate the difference between the target angular velocity fluctuation and the feedback angular velocity to obtain the first angular velocity difference; the feedback angular velocity is the sum of the DC component P_DC of the angular velocity compensation P_out and the compensated angular velocity output Δω'; Perform filtering processing on the first angular velocity difference to obtain a filtered angular velocity after filtering out at least part of the angular velocity fluctuation; Inputting the filtered angular velocity as an input to a speed loop regulator in the compressor control speed loop to obtain the output torque of the speed loop regulator; controlling the compressor according to the output torque; The filtering process on the first angular velocity difference to obtain a filtered angular velocity after filtering out at least part of the angular velocity fluctuation specifically includes: A velocity fluctuation extraction algorithm is used to extract part of the angular velocity fluctuation in the first angular velocity difference, extract the DC component of the partial angular velocity fluctuation, and calculate the difference between the first angular velocity difference and the DC component of the partial angular velocity fluctuation , the difference is determined as the filtered angular velocity. 2. The method according to claim 1, characterized in that, performing filtering processing on the shaft error Δθ to obtain a corrected shaft error Δθ' after filtering out at least part of the shaft error fluctuation, specifically comprising: Perform filtering processing on the shaft error Δθ, at least filter out the first harmonic component in Δθ, and obtain a corrected shaft error Δθ' that filters out at least the first harmonic component. 3. The method according to claim 2, characterized in that, performing filtering processing on the shaft error Δθ, further comprising filtering out the second harmonic component in Δθ, and obtaining the filtered first harmonic component and Δθ. Correction axis error Δθ' of the second harmonic component. 4. The method according to claim 2, wherein the following process is used to obtain the corrected axis error Δθ' that filters out the first harmonic component and the angular velocity compensation amount P_out corresponding to the corrected axis error Δθ': Expand the axis error Δθ as a Fourier series to obtain the function expression of the axis error with respect to the mechanical angle θ _m ; The first harmonic component of the shaft error Δθ is extracted from the function expression, and the first harmonic component is filtered out by an integrator to obtain a filtering result; The filtering result is subjected to inverse Fourier transform to obtain the angular velocity compensation amount P_out corresponding to the corrected axis error Δθ' for filtering out the first harmonic component. 5 . The method according to claim 4 , wherein the extracting the first harmonic component of the shaft error Δθ from the functional expression specifically comprises: 6 . Using the low-pass filtering method or the integration method, the first harmonic component of the shaft error Δθ is extracted from the functional expression. 6. The method according to any one of claims 1 to 5, wherein the extracting part of the angular velocity fluctuations in the first angular velocity difference using a velocity fluctuation extraction algorithm specifically includes: Using a velocity fluctuation extraction algorithm, at least the first harmonic component in the first angular velocity difference is extracted as the partial angular velocity fluctuation. 7 . The method according to claim 6 , wherein the extraction of the first harmonic component in the first angular velocity difference by using a velocity fluctuation extraction algorithm specifically includes: 8 . Expand the first angular velocity difference as a Fourier series to obtain a functional expression about the mechanical angle; Extract the d-axis component and the q-axis component of the first harmonic respectively from the functional expression; The d-axis component and the q-axis component of the first harmonic are added to obtain the first harmonic component in the first angular velocity difference. 8 . The method according to claim 6 , wherein the extracting part of the angular velocity fluctuations in the first angular velocity difference by using a velocity fluctuation extraction algorithm further comprises: using a velocity fluctuation extraction algorithm to extract the For the second harmonic component in the first angular velocity difference, the sum of the first harmonic component and the second harmonic component is used as the partial angular velocity fluctuation. 9 . The method according to claim 8 , wherein the extraction of the second harmonic component in the first angular velocity difference by using a velocity fluctuation extraction algorithm specifically includes: 10 . Expand the first angular velocity difference as a Fourier series to obtain a functional expression about the mechanical angle; Extract the d-axis component and the q-axis component of the second harmonic respectively from the functional expression; The d-axis component and the q-axis component of the second harmonic are added to obtain the second harmonic component in the first angular velocity difference. 10. The method according to claim 1, wherein the target angular velocity fluctuation is 0; the real-time angular velocity ω1 used for compressor control is corrected according to the compensated angular velocity output Δω', according to The modified real-time angular velocity ω1 controls the compressor, which specifically includes: adding the compensated angular velocity output Δω' to a given angular velocity command, and the addition result is determined as the corrected real-time angular velocity ω1, according to the The modified real-time angular velocity ω1 controls the compressor.

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